Anchor having fixing device at side of pressure plate to depress land slope and method of installing same

ABSTRACT

The present invention relates to an earth retaining structure for reinforcing a slope, and more particularly, to an anchor including a fixing body at a pressure plate side for compressing a slope and a method for installing the anchor in the slope. The anchor including a fixing body at a pressure plate side for compressing a slope capable of preventing tension of the anchor from being lost by installing a friction type pressure plate fixing body in a steel pipe form that is integrated with the pressure plate at the pressure plate side of the anchor, installing a primary packer at a middle part of the anchor to conduct pressurized-grouting to fix a tip end side fixing body of the anchor, compressing a large pressure plate compressing the slope by introducing a tensile force to the tension member of the anchor together with the pressure plate side fixing body, expanding a secondary packer, and conducting secondary pressurized-grouting, is provided.

BACKGROUND 1. Field

The present invention relates to an earth retaining structure forreinforcing a slope, and more particularly, to an anchor including afixing body at a pressure plate side for compressing a slope and amethod for installing the anchor in the slope.

2. Description of Related Art

Generally, in civil engineering works for constructing a road, arailway, a bank, portals of a tunnel, an apartment complex, etc., a cutslope or an embankment slope often occur. In such a cut slope or anembankment slope, sliding and erosion occur. For prevent the sliding andthe erosion and being in harmony with the natural environment, anenvironmental-friendly slope reinforcement method has been required.

A soil nailing method that has been generally performed as the slopereinforcement method has a problem in that it has a structure in whichthe slope is reinforced only by a frictional force of a nail, thus alarger number of nails are needed for reinforcement as compared to astructure of reinforcement using tension of an anchor.

As another slope reinforcement method, a reinforced concrete retainingwall has been mainly used. However, it is disadvantageous in that alarge cost and time are required for installation of a reinforcedconcrete structure, thus an anchor is additionally installed while beingintegrated with the reinforced concrete retaining wall. However, thisreinforcement method is also disadvantageous in that large costs arerequired for earthworks and banking works, and an entire size of astructure is also increased.

If the slope is cut, stress distribution is changed, and an undergroundwater level is lowered such that the ground is subsidence. Thephenomenon as described above occurs to a remarkable degree in arelatively soft soil and weathered rock ground. Accordingly, even whenan anchor is installed at the time of excavating the slope and the slopeis compressed using a large pressure plate, the pressure plate part issubsidence over time, such that a tension of the anchor is lost, as aresult, there is no reinforcing effect.

Further, in a region having clear four seasons, the soil is softened dueto repetition of freezing and thawing, thus the pressure plate bearingcontinuous compression is subsidence, as a result, the tension of theanchor is lost.

SUMMARY

An object of the present invention is to provide an anchor including afixing body at a pressure plate side for compressing a slope capable ofpreventing tension of the anchor from being lost by installing afriction type fixing body in a steel pipe form that is integrated withthe pressure plate at a tension side of the anchor, installing a primarypacker at a middle part of the anchor to conduct pressurized-grouting tofix the fixing body at a tip end side of the anchor, compressing a largepressure plate compressing the slope by introducing a tensile force tothe tension member of the anchor together with the pressure plate sidefixing body at the pressure plate side, expanding a secondary packer,and conducting secondary pressurized-grouting, and a method forinstalling the same.

According to an aspect of the present invention, an anchor including afixing body at a pressure plate side for compressing a slope that isconfigured of a tension member for introducing a tensile force byconnecting the pressure plate installed to compress the slope and a tipend side fixing body fixed to an original ground by grouting, the anchorincludes a primary packer installed at a middle part of the tensionmember to conduct primary grouting on the tip end side fixing body andfixing the tip end side fixing body, a secondary packer installed at thepressure plate side fixing body, and the pressure plate side fixing bodycoupled to a pressure plate compression ring configured to be fixed bysecondary grouting after the secondary packer is expanded to beintegrally behaved with the pressure plate capable of exhibiting asupport force even at a soft ground slope.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a view generally illustrating a state in which a pressureplate is compressed by an anchor including a fixing body at the pressureplate side for compressing a slope.

FIG. 2 is a view separately illustrating the fixing body of the pressureplate side.

FIG. 3 is a view illustrating a friction type tip end side fixing bodyof the anchor according to the present invention.

FIG. 4 is a cross-sectional view taken along line A-A′ in FIG. 1, whichillustrates a position where a bag-packer is installed in a state inwhich a tip end side fixing body 6 is fixed by grouting and a pressureplate side fixing body 5 is installed in a drilled hole.

FIG. 5 is a cross-sectional view taken along line B-B′ in FIG. 1, whichillustrates a cross section of a tension member configured of a primaryinjection hose 12 for first fixing the tip end side fixing body bygrouting, a primary packer injection hose 11, a discharge hose 14, thetension member 9, and a secondary injection hose 13.

FIG. 6 is a cross-sectional view taken along line C-C′ in FIG. 1, whichillustrates the tip end side fixing body 6.

FIG. 7 is a view illustrating a hose cutter configured to be installedat an angle of 40 to 50 degrees on a long steel rod, and formed with asharp blade at an inner side of a steel plate of hose cutter with a holeso that the hose cutter is put into the hose and pulled, the hose iscut.

FIG. 8 is view illustrating pressure plates according to variousembodiments of the present invention.

DETAILED DESCRIPTION

Hereinafter, an anchor according to the present invention will bedescribed in detail with reference to the accompanying drawings.

Describing terms in the present invention in detail, a part fixed to theground by grouting or bearing on a ground pressure is defined as a“fixing body”, the fixing body at a right tip end of FIG. 1 is definedas a “tip end side fixing body 6” and the fixing body having thepressure plate and a head of the left side is defined as a “pressureplate side fixing body 5”. In the present invention, the “soft ground”refers to the ground in which an exposed part of a slope is soil or aweathered rock and the pressure plate is subsidence due to a prolongedtension of the anchor.

FIGS. 1 to 8 are views generally illustrating an anchor 50 according tothe present invention, in which the anchor is inserted into a drilledhole 22 and grouting is performed to compress a pressure plate 1 to aslope. Throughout the drawings, the same reference numeral denotes thesame component.

FIG. 1 is a view generally illustrating the anchor 50 according to thepresent invention, and the anchor that is configured of a tension member9 for introducing a tensile force by connecting a pressure plate 1installed to compress the slope and a tip end side fixing body 6 fixedto an original ground by grouting, includes a primary packer 7 installedat a middle part of the tension member 9 to conduct primary grouting onthe tip end side fixing body 6 and fixing the tip end side fixing body,a secondary packer 8 installed at the pressure plate side fixing body 5,and the pressure plate side fixing body coupled to a pressure platecompression ring 4 configured to be fixed by secondary grouting afterthe secondary packer 8 is expanded to be integrally behaved with thepressure plate 1 capable of exhibiting a support force even at a softground slope.

The anchor 50 according to the present invention includes the tensionmember 9 having a length longer than a length of the drilled hole 22 anda thickness of the pressure plate 1, an anchor head 2 and a tip end sideanchor head 15 formed at both ends of the tension member 9, an anchorcap 3 covering the anchor head 2, the pressure plate 1 compressing theslope at a left side of the tension member 9, the pressure plate sidefixing body 5 coupled to the pressure plate compression ring 4 that isfitted into the hole 19 of the pressure plate 1 by welding or using acoupling means such as a screw, the tip end side fixing body 6positioned opposite to the pressure plate side fixing body 5, theprimary packer 7 positioned at the middle part of the tension member 9,two shrinkable tubes 10 fitted on the tension member 9 and positioned atboth sides of the primary packer 7 while being spaced apart from theprimary packer 7 by a predetermined distance, the secondary packer 8installed at the pressure plate side, a secondary injection hose 13installed in the anchor 50, a primary packer injection hose 11 extendingover the tip end side fixing body 6 through the pressure plate sidefixing body 5, a primary injection hose 12, a discharge hose 14, asecondary packer injection hose 16, a temporary packer blocking thepressure plate compression ring at the time of secondary grouting, and ahose cutter 21 for cutting the primary injection hose 12.

The tension member 9 is formed of a single wire or a plurality of wires,and is coated with a PE tube 24 so that it is smoothly elongated at thetime of extension after cement grouting, thereby preventing an injectinggrouting material is not attached. In the present specification, a casein which the tension member 9 formed of four groups is installed isillustrated.

The pressure plate side fixing body 5 of FIG. 2 is configured to beintegrally behaved when the pressure plate compression ring 4 in aflange form is coupled to a tip end of a steel pipe 18 by welding orusing a coupling means such as a screw, and the pressure platecompression ring 4 coupled to the hole 19 of the pressure plate and thefixing body in the steel pipe form extend the tension member 9 using theanchor head 2. At this time, the pressure plate compression ring 4 neednot necessarily have a circular shape, but may have various shapes suchas a tetragonal shape, a hexagonal shape, and the like.

The steel pipe 18 of the pressure plate side fixing body 5 is configuredto have uneven parts formed at an outer surface thereof and have largefriction force by grouting, a steel pipe hole 17 is formed in the tipend side of the steel pipe from the secondary packer 8 so that theinjecting grouting material in the inside is also injected to theoutside of the steel pipe at the time of grouting, the secondary packer8 has a bag-packer form, is formed on the outside of an imperforatesteel pipe part, and is provided with the secondary packer injectionhose and a secondary discharge hose penetrating through the packer, andthe primary injection hose and the primary packer injection hosepenetrate therethrough to be additionally installed. In a morepreferable embodiment, in order to prevent leakage of the secondarypacker, the pressure plate side fixing body 5 is configured so that theprimary injection hose 12 through which the primary injection iscompleted and the primary packer injection hose 11 are cut by the hosecutter 21 at a depth of about 2 m of the drilled hole, and only thesecondary packer is installed.

The tip end side fixing body 6 of FIG. 3 is a friction type fixing body,and the tip end side anchor head 15 serves to fix the tension member 9.As a fixing body outside the tension member 9, various types of fixingbody such as a bearing type, a combination type of the bearing type andthe friction type, and the like may be applied.

FIG. 4 is a cross-sectional view taken along line A-A′ in FIG. 1, whichillustrates a position where the secondary bag-packer is mounted in astate in which the tip end side fixing body 6 is fixed by grouting andthe pressure plate side fixing body 5 is installed in the drilled hole22.

FIG. 5 is a cross-sectional view taken along line B-B′ in FIG. 1, whichillustrates a cross section of the tension member configured of theprimary bag-packer, the primary injection hose 12 for first fixing thetip end side fixing body 6 by grouting, the primary packer injectionhose 11, the discharge hose 14, the tension member 9, and the secondaryinjection hose 13.

FIG. 6 is a cross-sectional view taken along line C-C′ in FIG. 1, whichillustrates the tip end side fixing body 6.

FIG. 7 illustrates the hose cutter 21 that is configured to be installedat an angle of 40 to 50 degrees, preferably, 45 degrees on a long steelrod 23, and formed with a sharp blade at an inner side of a steel plateof hose cutter with a hole so that when the injection hoses 11 and 12 orthe discharge hose 14 is put into the hole of the hose cutter andpulled, the injection hoses 11 and 12 or the discharge hose 14 is cut.The hose cutter 21 is used at the time of cutting the injection hoses 11and 12, and the discharge hose 14 in the drilled hole 22.

FIG. 8 is view illustrating pressure plates having various shapes suchas a cross shape, a tetragonal shape, etc., and cross-shaped pressureplates 1 may be connected to each other to form a lattice form.

The anchor which is configured of the tension member 9 for introducing atensile force by connecting the pressure plate 1 installed to compressthe slope and the tip end side fixing body 6 fixed to the originalground by grouting, includes the primary packer 7 installed at a middlepart of the tension member 9 to conduct primary grouting on the tip endside fixing body 6 and fixing the tip end side fixing body 6, thesecondary packer 8 installed at the pressure plate side fixing body 5,and the pressure plate side fixing body 5 coupled to the pressure platecompression ring 4 configured to be fixed by secondary grouting afterthe secondary packer 8 is expanded to be integrally behaved with thepressure plate 1 capable of exhibiting a support force even at a softground slope.

As the main technical idea and characteristics of the present invention,if the slope is cut, restrained stress is released to change stressdistribution, and an underground water level is lowered, such thatplastic deformation of the soft ground occurs. The phenomenon asdescribed above occurs to a remarkable degree in a relatively soft soiland weathered rock ground. Accordingly, even when the anchor 50 isinstalled at the time of excavating the slope and the slope iscompressed using the large pressure plate 1, the pressure plate 1 partis subsidence over time, such that a tension of the anchor 50 is lost,as a result, there is no reinforcing effect.

Further, in a region having clear four seasons, the soil is softened dueto repetition of freezing and thawing, thus the pressure plate 1 bearingcontinuous compression is subsidence, as a result, the tension of theanchor 50 is lost.

In order to solve the above problems, the friction type pressure plateside fixing body 5 in a steep pipe form integrated with the pressureplate is installed at the tension side of the anchor 50, therebypreventing loss of tension of the anchor 50.

Further, the primary packer is installed at a middle part of the anchor50 to conduct pressurized-grouting to fix the fixing body 6 at the tipend side of the anchor, the large pressure plate 1 compressing the slopeis compressed by introducing a tensile force to the tension member 9 ofthe anchor together with the pressure plate side fixing body, thesecondary packer 8 is expanded, and the secondary pressurized-groutingis conducted, thereby completing the process.

According to a preferred embodiment of the present invention, a methodfor installing an anchor includes: forming a drilled hole 22 in a slopeof the soft ground such as soil and weathered rock, inserting the anchor50 in which a tip end side fixing body 6 and a tension member 9 arecoupled, and then conducting grouting up to a part where a primarypacker 7 is installed at a middle part of the anchor 50 for grouting ofthe tip end side fixing body 6 of the anchor; installing a pressureplate 1 on a tension member 9 of the anchor and fitting a pressure plateside fixing body 5 to which a pressure plate compression ring 4 iscoupled on the tension member 9 to be inserted and installed in thedrilled hole 22; expanding a secondary packer 8 installed at a tip endof the pressure plate side fixing body 5; installing an anchor head 2 onthe pressure plate 1 and extending the tension member 9; and conductingsecondary grouting.

Considering site conditions, according to a second embodiment of thepresent invention, a method for installing an anchor includes: insertingan anchor 50 in which a tip end side fixing body 6, a tension member 9,and a pressure plate side fixing body 5 are integrally assembled into adrilled hole 22 in a slope, and expanding a packer to conduct grouting;fitting a pressure plate 1 on the pressure plate side fixing body 5 andthen screw-coupling a pressure plate compression ring to be fastened;and extending and fixing a tension member 9 of the anchor that protrudesfrom a pressure plate hole 19 using an anchor head 2.

The pressure plate side fixing body 5 is configured to be integrallybehaved when the pressure plate compression ring 4 in a flange form iscoupled to a tip end of a steel pipe by welding or using a screw, andthe pressure plate compression ring 4 coupled to the pressure plate holeand the pressure plate side fixing body 5 in the steel pipe form extendthe tension member 9 by a hydraulic jack using the anchor head 2.

The steel pipe 18 of the pressure plate side fixing body 5 is configuredto have uneven parts formed at an outer surface thereof and have largefriction force by grouting, a steel pipe hole 17 is formed in the tipend side of the steel pipe 18 from the packer so that the injectionmaterial in the inside is also injected to the outside of the steel pipe18 at the time of grouting, the secondary packer 8 has a bag-packerform, is formed on the outside of an imperforate steel pipe part, and isprovided with a secondary packer injection hose 16 and a secondarydischarge hose penetrating through the packer, and a primary injectionhose 12 and a primary packer injection hose 11 penetrate therethrough tobe installed. In a more preferable embodiment, in order to preventleakage of the packer, the primary injection hose 12 through which theprimary injection is completed and the primary packer injection hose 11are cut by a hose cutter 21 at a depth of about 2 m of the drilled hole22. By cutting the hoses as described above, the primary packerinjection hose 11 and the primary injection hose 12 do not penetratethrough the secondary packer 8, the secondary packer 8 is simplyconfigured and may be easily installed. At the time of secondarygrouting, the discharge hose is not needed, and a temporary packer isinstalled at the pressure plate compression ring of the pressure plateside fixing body 5 to inject a grout solution. At the time of secondaryinjection, in a case of the ground in which the pressure plate 1 and theslope are compressed closely, the secondary packer 8 may be omitted.

As the tip end side fixing body 6, various existing fixing bodies may beused. In FIG. 3, the tip end side fixing body 6 of the anchor 50 is afriction type fixing body, and the tip end side anchor head 15 serves tofix the tension member 9. As a fixing body 20 outside the tension membercoupled to the anchor head 2, various types of fixing body such as abearing type, a combination type of the bearing type and the frictiontype, and the like may be applied.

In designing the anchor, a support ability of the pressure plate and thepressure plate side fixing body needs to be larger than a tensile loadof the tension member, and a support ability of the tip end side fixingbody also needs to be larger than the load introduced to the tensionmember.

According to the present invention, the friction type pressure plateside fixing body in a steel pipe form that is integrated with thepressure plate and behaved integrally at the pressure plate side of theanchor, are installed deeper than the freezing depth, such that it ispossible to prevent the settlement caused by the phenomenon that thesoil is softened due to repetition of freezing and thawing occurring inthe region having clear four seasons.

Even in the soft ground that may not bear the bearing pressure of thepressure plate, the friction type pressure plate side fixing body in asteel pipe form may reinforce the support force for the soft ground by africtional force.

The friction type pressure plate side fixing body in a steel pipe formthat is integrated with the pressure plate are installed deeper than theeffect zone from the slope, such that it is possible to preventadditional settlement of the pressure plate bearing continuouscompression and loss of tension of the anchor, in spite of the loweringof the underground water level and the change in stress.

Further, the pressure plate side fixing body has the same effect as thenailing, and since the pressure plate is fixed to the friction typepressure plate side fixing body in a steel pipe form, deformation of atensile force does not occur, and it is possible to safely performextension even when there is a need to perform extension again.

DESCRIPTION OF REFERENCE NUMERALS

1 pressure plate

2 anchor head

3 anchor cap

4 pressure plate compression ring

5 pressure plate side fixing body

6 tip end side fixing body

7 primary packer

8 secondary packer

9 tension member

10 shrinkable tube

11 primary packer injection hose

12 primary injection hose

13 secondary injection hose

14 discharge hose

15 tip end side anchor head

16 secondary packer injection hose

17 steel pipe hole

18 steel pipe

19 pressure plate hole

20 fixing body

21 hose cutter

22 drilled hole

23 long steel rod

24 PE pipe

50 anchor

What is claimed is:
 1. An anchor including a fixing body at a pressureplate side for compressing a slope, and configured of a tension memberfor introducing a tensile force by connecting a pressure plate installedto compress the slope and a tip end side fixing body fixed to anoriginal ground by grouting, the anchor comprising: a primary packerinstalled at a middle part of the tension member to first conductprimary grouting on the tip end side fixing body and fixing the tip endside fixing body; and the pressure plate side fixing body coupled to apressure plate compression ring configured to be fixed by secondarygrouting after the secondary packer is expanded to be integrally behavedwith the pressure plate exhibiting a support force even at a soft groundslope.
 2. The anchor of claim 1, wherein in a steel pipe of the pressureplate side fixing body, a steel pipe hole is formed in a tip end side ofthe steel pipe from the secondary packer so that an injection materialin the inside of the steel pipe is also injected to the outside of thesteel pipe at the time of grouting.
 3. A method for installing an anchorincluding a fixing body at a pressure plate side for compressing aslope, the method comprising: forming a drilled hole in a slope of asoft ground, inserting the anchor in which a tip end side fixing bodyand a tension member are coupled, and then expanding a primary packer ata middle part of the anchor for grouting of the tip end side fixing bodyof the anchor and conducting grouting up to a part where the primarypacker is installed; installing a pressure plate on the tension memberof the anchor and fitting the pressure plate side fixing body to which apressure plate compression ring is coupled on the tension member to beinserted and installed in the drilled hole; expanding a secondary packerinstalled at a tip end of the pressure plate side fixing body;installing an anchor head on the pressure plate and extending thetension member; and conducting secondary grouting on the pressure plateside fixing body.
 4. A method for installing an anchor including afixing body at a pressure plate side for compressing a slope, the methodcomprising: inserting the anchor in which a tip end side fixing body, atension member, and the pressure plate side fixing body are integrallyassembled into a drilled hole in a slope, and expanding a primary packerto conduct grouting; fitting a pressure plate on the pressure plate sidefixing body and then screw-coupling a pressure plate compression ring tobe fastened; and extending and fixing the tension member of the anchorthat protrudes from a pressure plate hole using an anchor head, andcovering with an anchor cap; and conducting secondary grouting on thepressure plate side fixing body.